1. Industrial Field
This invention relates to a magnetic bearing device and, more particularly, to a single shaft control type magnetic bearing device being formed into an active magnetic bearing in the direction of rotary shaft, while being formed into a passive magnetic bearing in radial direction.
2. Prior Art
Generally, in magnetic bearings of single shaft control type, two opposite sides of a rotor are supported by a passive magnetic bearing in radial direction. However, damping characteristics of this passive magnetic bearing in radial direction are not always preferable and amplitude magnification thereof at resonance point is large. To prevent accident at the time of passing resonance point, a damper making use of eddy current or a damper whose stator section is movable by metal spring is adopted as countermeasure. However, the damper making use of eddy current has a problem of poor damping characteristics, and the damper of movable stator section has a problem of being easily affected by disturbance and troublesome in assembly thereof.